U.S. Pat. No. 7,735,502 (Hotes) illustrates a heating, ventilating and air conditioning unit for a temporary flexible shelter.
U.S. Pre-Grant Publication 2009/0228149 (Alston '149) refers to an environment control and power system for a temporary hospital or first-aid shelter operated by military or other emergency response services. The Alston system is said to have a variable speed compressor, and the respective compressor and blower speeds are said to be automatically set. Alston also refers to an electric resistance heater, and a user interface, which is said to control humidity.
U.S. Pre-Grant Publication 2008/0311842 (Alston '842) refers to a forced-air heating, ventilating and air conditioning system that routes air, through a diverter Y valve, to different locations, based on sensed conditions, including temperature and hazardous conditions, or under the control of a user interface.
U.S. Pre-Grant Publication 2012/0191253 (Rockenfeller) refers to a heating, ventilation, air conditioning, and refrigeration system for a residential home, commercial building or remote location. Rockenfeller refers to variable frequency drives for controlling the speeds of a blower and a compressor motor.
The known systems are not sufficiently light weight, efficient, rugged and reliable, and safe, especially for use in remote, extreme environments. There is a need in the art for an HVAC unit that is better suited for operations where the unit has to be moved and installed by hand, where fuel for generating electric power is scarce and expensive, where weather conditions include very high and low temperatures, rapid, large changes in temperature, and high humidity, and/or where rapid set-up, reliability, and safe performance are at a premium.